Blood transfusion is an essential part of modern healthcare and can be life saving when used appropriately. Blood services worldwide strive to provide a safe supply and work with hospitals to ensure that blood products are readily available for patients. Blood components such as red cells, platelets, fresh frozen plasma, cryoprecipitate, and granulocytes are prepared from whole blood donations or collected by apheresis. Plasma derivatives such as coagulation factor concentrates, immunoglobulins, and albumin are prepared from large pools of plasma under drug manufacturing conditions. The process of getting a unit of blood from a donor to a patient is complex. Many steps are taken to ensure that the transfusion is as safe as possible. Although serious complications of blood transfusion are uncommon, patients should be transfused using evidence based guidelines. This will minimise any adverse effects and ensure that blood products, which are donated by volunteers and are costly and sometimes in short supply, are used appropriately. Every effort should be made to reduce or eliminate the need for transfusion by considering alternative approaches to patient management. Patients should be in clinical need of transfusion and should understand why transfusion is being recommended. The aim of this review is to describe best practices for the safety of patients receiving blood transfusions, including ways to reduce unnecessary transfusions.